The functional vessels of human and animal bodies, such as blood vessels and ducts, occasionally weaken or even rupture. For example, the aortic wall can weaken, resulting in an aneurysm, or it may develop a tear in one of the layers of the aortic wall resulting in an aortic dissection.
One common surgical intervention for weakened, aneurysmal or ruptured passageways or ducts involves the use of an endoluminal prosthesis to provide some or all of the functionality of the original, healthy passageway or duct and/or preserve any remaining vascular integrity by replacing a length of the existing passageway or duct wall that spans the site of failure or defect. Endoluminal prostheses may be of a unitary construction or may be comprised of multiple prosthetic modules. They also may be a single tubular device or a bifurcated branching device depending on the desired application.
In many cases, however, the damaged or defected portion of the vasculature may include a branch vessel branching from the main vessel. For example, in the case of the abdominal aorta, there are at least three major branch vessels, including the celiac, mesenteric, and renal arteries, as well as other others, leading to various other body organs. Thus, when the damaged portion of the vessel includes one or more of these branch vessels, some accommodation must be made to ensure that the prosthesis does not block or hinder blood flow through the branch vessel. In many instances, there may in insufficient healthy tissue in the aorta near the branching vessels adequately seal a prosthesis without partially or completely blocking one or more of the branching vessels.
In some cases, a patient's anatomy may not include, for example, a renal artery one side, or it may not be possible to cannulate one of the renal arteries. These conditions can result in an unused passageway of the prosthesis intended for use with a typical renal artery in the area of the unused passageway. These passageways can be closed using endovascular plugs or other devices. Alternatively, the prosthesis can undergo “back table” modification, wherein the prosthesis is deployed from its sheath, a patch can be sewn over the passageway, the prosthesis is re-sheathed, and then the prosthesis can be implanted using known methods. In another alternative, a custom device can be made to conform to the patient's unique anatomy. These solutions, however, are undesirably labor intensive or costly.